The present invention relates to a multi-layer container in the form of a body of rotation having a plurality of layers wrapped upon each other. The container has at least one longitudinal seam per layer provided by adjacent longitudinal edges and comprises a core or core pipe as well as the plurality of layers wrapped therearound. Such containers are particularly useful as pressure containers or vessels for chemical and petroleum substances.
For purposes of making such a multi-layer container, first pre-formed sheet metal layers are tensioned around the core pipe. Subsequently the layers are tensioned around the respective preceding layer. The layers are pressed relative to each other so that an engagement as complete as possible will be realized. Only in this way, will there be assured the necessary uniform load distribution over all layers. During the tensioning of the layers, the layer ends or edges of seams are at some points only fastened by tack welding and subsequently are completely welded, as required.
It is an object of the present invention to provide a multi-layer container of the above mentioned general type which is considerably improved over previous container structures.